It is known that many livestock enterprises and stock-farms prepare the ration of food to be administered to each animal using a mixing unit consisting of a mixing wagon comprising a bin in which several food products are loaded by means of an external loader unit comprising, for example, an engine-driven vehicle with mechanical shovel. The mixer wagon also comprises one or more augers arranged inside the bin to mix the food products in the bin. The food products are loaded in the bin of the mixer wagon in a specific order according to the weights established by a recipe prepared previously by a nutritionist. Typically, each animal has different nutritional requirements according to breed, stage of growth and general conditions. Furthermore, the animals are divided into groups characterised by similar nutritional requirements. Therefore, each stock-farm has to prepare several food product recipes.
A prior art mixer wagon is equipped with a weighing device comprising load cells coupled with the bin in order to detect the weight of the contents of the bin, and a control unit connected to the load cells in order to check loading of the food products. The control unit comprises a memory in which one or more recipes are saved, a keyboard for entry of data and commands by an operator dedicated to the mixer wagon, for example to select the recipe, a processing unit to run a load programme defined by the recipe selected, a display to show information during execution of the recipe, for example to display the current weight recorded by the load cells and a buzzer to indicate that the pre-established weight of each food product has been reached.
In use, the load program scans the food products to be loaded in a certain order established by the selected recipe and emits an operator alarm when the pre-established weight of each food product is reached so that the operator may order the loader unit to load the next food product. The alarm is emitted, for example, in the form of an acoustic signal by means of a buzzer and/or in the form of a visual signal by means of the display. The loader unit takes each food product to be loaded from at least one relative stocking area.
Using the aforementioned control unit, the operator of the mixer wagon controls the quantity of each food product loaded. However, the operator of the mixer wagon does not have the possibility of automatically and accurately checking that each food product loaded by the loader unit in the mixer wagon is that effectively established by the recipe. In other words, the operator personally verifies that the stocking area from which the loader unit takes the food product is the correct area for the food product programmed.